FORTUNE's Best Companies to Work for 2011

Each year Fortune compiles its list of the 100 Best Companies to Work For. Based largely on employee surveys, this list is significant for all those who are not just looking for a job, but also a great experience at work.

We've listed the top ten of Fortune's 2011 list below. This year eight of the top ten companies from last year were able to maintain there exclusive ranking. The two new additions are companies you've likely heard of before; they're online shoe retailer Zappos.com and outdoor product purveyor Recreational Equipment (REI)

So without further adieu, here are the top ten companies to work for...

01. SAS

Rank: 1 (Previous rank: 1)

What makes it so great?

A 14-year veteran of this list, the software firm takes the top spot for the second year running.

Its perks are epic: on-site healthcare, high quality childcare at $410 per month, summer camp for kids, car cleaning, a beauty salon, and more -- it's all enough to make a state-of-the-art, 66,000-square-foot gym seem like nothing special by comparison.

This year, strong employee feedback sent its numbers even higher. Says one manager: "People stay at SAS in large part because they are happy, but to dig a little deeper, I would argue that people don't leave SAS because they feel regarded -- seen, attended to and cared for. I have stayed for that reason, and love what I do for that reason."

02. Boston Consulting Group

Rank: 2 (Previous rank: 8)

What makes it so great?

The consulting giant not only avoided layoffs in the downturn, but hired its largest class of recruits ever in 2010.

They're drawn by the firm's generous pay and a commitment to social work: Its Social Impact Practice Network (SIPN) offers a chance to work with the U.N. World Food Program and Save the Children, while BCG pulled its consultants off client projects to provide on-the-ground support in Haiti following the earthquake.

03. Wegmans Food Markets

Rank: 3 (Previous rank: 3)

What makes it so great?

This customer-friendly supermarket chain cares about the well-being of its workers, too. This year, 11,000 employees took part in a challenge to eat five cups of fruit and vegetables a day and walk up to 10,000 steps a day for eight weeks.

Another 8,000 took advantage of health screenings that included a flu shot and H1N1 vaccine -- all covered by Wegmans.

04. Google

Rank: 4 (Previous rank: 4)

What makes it so great?

The search giant is famous for its laundry list of perks including free food at any of its cafeterias, a climbing wall, and, well, free laundry.

Last year, with revenue up more than 20%, Google sweetened this already rich pot of perks by giving every employee a 10% pay hike. Googlers can also award one another $175 peer spot bonuses -- last year more than two-thirds of them did so.

06. Zappos.com

Rank: 6 (Previous rank: 15)

What makes it so great?

The online shoe retailer makes a big leap from no. 15 to no. 6 this year.

Now part of the Amazon.com family, the company's quirky, happy culture remains: Employees enjoy free lunches, no-charge vending machines, a full-time life coach on hand, and "create fun and a little weirdness" as one of the company's guiding tenets.

08. Nugget Market

Rank: 8 (Previous rank: 5)

What makes it so great?

Rallies are an everyday event at this nine-store Northern California supermarket chain, where management uses a big flat screen computer monitor in each store to deliver important information about products, messages from the leadership team, employee awards, and pump up the troops.

Employees who watch diligently can be rewarded with bonuses that range from $20 to $1,500. Universal perk: everyone receives a 10% discount on store purchases.